268 



nishes a grand field for their action after they are started on 

 their career from other points. 



It is the object of this paper to inquire as to whether these 

 conditions can be modified and to indicate what appears to be 

 the 



SOLUTION OF THE PROBLEM. 



But first we must note that this ocean or atmosphere is impelled 

 in all its movements by identically the same force that moves 

 the ocean of water, namely, gravity. All our atmospheric 

 movements are simply adjustments of equilibrium. To appreci- 

 ate how these movements occur, we have only to study the 

 analagous movements of water currents. Water runs down 

 hill. The air does exactly the same thing. As streams of 

 water flow down from the mountains into the valleys in well 

 defined channels, just so do the atmospheric currents move 

 down from areas of high pressure, and are guided by the con- 

 figuration of the lands over which they flow. This is the sim- 

 ple problem, but it is generally rendered complex by the 

 intervention of other factors. The states of Indiana, Illinois, 

 Iowa, Missouri and eastern Kansas, when considered in relation 

 to sea-level, occupy a very low position. Any disturbance of 

 the atmosphere above them, from whatever cause, either from 

 shifting up by sun heat or a movement to supply the needs of 

 other regions southeastward of us over the Atlantic would 

 naturally lead to a flow of air from the higher lands westward 

 of us. The rapidity and volume of this reinforcing stream will 

 depend on two causes : First, the declivity of the hill down 

 which it comes and the size of the space to be filled up. We 

 can measure this descent, which has two elements, one of alti- 

 tude and another of pressure. We can also measure the space 

 to be filled — the barometer shows this without fail. 



IN THIS LOCALITY 



whenever we have an area of low pressure — which is nearly 

 constant in the months of May, June and July — we must expect 

 the equilibrium to be restored by an in-rush of air from the 



